Is there any empirical support for biodiversity offset policy

摘要: Biodiversity offsets are seen as a policy mechanism to balance development and conservation goals. Many offset schemes employ habitat restoration in one area recreate biodiversity value that is destroyed elsewhere, assuming recovery timely predictable. Recent research has challenged these assumptions on the grounds implies long time delays low certainty of success. To investigate assertions, assess strength empirical support for policy, we used meta-analytic approach analyze data from 108 comparative studies secondary growth (SG) old-growth (OG) (a total 1228 SG sites 716 OG reference sites). We extracted species checklists calculated standardized response ratios richness, Fisher's alpha, Sorenson similarity, Morisita-Horn similarity. modeled diversity change with age using generalized linear models multi-model averaging, correcting number potential explanatory variables. tested whether (1) passively actively restored converges values over time, (2) active significantly accelerates this process, (3) current policies appropriate predicted uncertainties lags associated restoration. The results indicate best case, richness within century, similarity (Sorenson) takes about twice long, assemblage composition (Morisita-Horn) up an order magnitude longer (hundreds thousands years). Active process all indices, but inherently large lags, uncertainty, risk failure require far exceed what currently applied practice. Restoration therefore leads net loss biodiversity, represents inappropriate use otherwise valuable tool ecosystem